Piston for internal-combustion engines.



U. M. NACKER. PISTON FOR 'NTERNAL COMBUSTION ENGINES. A PPL ICATION FILED JAN. 19. 1917.

1,283,86. Patented Km. 5, 19125.

I v! I r /11711077170120; Q N g Q N jest is to prevent leakage around UNIT-en GWEN M. HACKER, OF DETROIT, MICHIGf-LN, ASSIGNGR (3F ONE-HALF 1'0 ALANSON P.

BRUSH, OF DETHQIT, IVTICHXGAN.

PISTON FOR INTERNAL-CGMBUSTiUN ENGINES. v

Application filed January 19, 191?. Serial No.

The. invention is a piston especially tlfl2l3t The ohed for internal combustion engines.

the piston, Without USIDQ; the commonly employed, ex-

pansible piston rings which, in the uccolh plislnnent of their purpose, press outward against a cylinder wall and cause undesirahle friction and consequent wear.

The invention consists in the construction and con'ibination of parts shown in the drawing and hereinafter described and definitely pointed out in the appended claims.

In, the drawing l igure l is a top plan view of the piston with the head thereof are moved, and Fig. 2 is a centrnl vertical sectionul view of a piston in which the invention is embodied.

In carrying out: the invention the piston is constructed with an annular rcess into which there is fitted a solid. 6., uusplit sleeve 10, which thin that it will con form to the (:vlinder walls even if the cyliu der be slightly out of round. )ulditioually. this sleeve is insulated from the body of the piston by a thin layer of asbestos iii, or other similar heat insulating-g n'iatorial. which sufficiently yielding to permit the thin sleeve to tlex to the extent nccwsary to conform to the cylinder walls as S.At(l.

Ol'H'lOUSly, pistons having' the above speci lied characteristics of the present invi itiou may be practically constructed in numerous ways. In the specific example shown in the drawing the piston is formed of iwo parts, namely. the body ii and the head 15 In the body and from its top downward for a distance of three or four inches, an anuulai recess is nmrhiued into the surface. and the sleeve 10 is slipped down in this annular recess with the asbestos packing l2 behind it 'until'l-he lower end of the sleeve rests upon the shoulder H at the lower end oi the annular recess. The sleeve held down in the described position by the piston head which is in turn held down by a centrally placed screw 18 which screws into a tapped boss 19. This boss is connected by arms 20 Specification of Letters Patent.-

- body.

liutented Nov. 5, 1918.

with the piston pin bosses 21 which are in tegral with the body partof tl'iepiston. An inwardly directed annular rib 13 may be formed on the upper end of the sleeve 10, and this ent and tits easily in an annular groove '14 in ihe upper end of the piston The sleeve 10 should be made of material which has substantially the same coefiicient of expansion as the cylinder in which it is to be employed. In order that the rib 13, which is thicker than the sleeve 10, may not. by its expansion and contraction, materially all e the external dian'ieter of the sleeve this rib is slottei'l in several dill'ercnt places.

External grooves l0 are formed in the outside of the piston sleeve. These are intended to function as oil carriers and oil packing grooves, wherefore there will usually be a film of oil between the surface of this sleeve and the opposed surface of the cylinder wall. The sleeve should lit the piston tightly enough to prevent leakage. If it does this under one of will do it under all of the coi'ulitions in use, because it will not be much expanded by heat l-runsinitled to it tron: the piston itself, and such expansion as does take place will take place and will be sub tantiully the same as the expan ion which takes 'ilace at the same time in the \vailsol' the cylinder.

Having thus described l claim 1. A p on cmnprisiug a body and a head which are scpnrahlv coi'ineclod together. said body havinggfan external annular recess ex tending from its top downward. and. the upper end oi said r cess being" deeper than the remainder. combined with an unsplit' thin walled flexible .i'nclullic sleeve uiadeof a metal having the same coellicicnt of expansion as the :uider with which this piston to be u I, which sleeve is loosely lifted into aid recess and has an inwardly extended notchm'l flange which projects into the (lC YPGl .(l part of said recess.

2. piston coinpr mg: a body and a head which are separalilv (OlllNlt'lHl loggcthcr. said body having an external annular recess extending from its top downward. and the upper end of sa d recess being deeperjthan the reruainder, conibii'led vvithan unsplitthin walled Flexible n'ietallic sleeve made of a metal having the same coellicieu: of expansion. as the cylinder with. which this piston the conditions in use it:

my invention, what is to be nsed, whichsleeve is loosely fitted into said recess-and has an inwardly extended notched flange which projects into the deepened part ofsaid recess, and a thin fi'psleeve of low heat-conducting material interposed between said metallic sleeve and the part of the piston embraced thereby.

H3UA piston comprising a hollow bodfi formed with internal piston bosses and with a longitudinal tapped boss which is connected by arms with said piston bosses,which body has an external annular recess extending from its top downward, combined with an unsplit thin'welled flexible metallic sleeve fitted t0 said'recess, andn head which en- 15 gages wlth the top of sald'sleeve and with the top of said body, and a screw which screws down through the piston into said OWEN M. NACK'ER. WVitnesses i THEODORE W. MARSH, PERCY F. Toni). 

